We are applying for a 5-year Renewal of our Biomedical Research Program. The program would consist of two projects, involving two faculty members, one secretary, and ten students. The projects would be in Biology and Chemistry. A third project may be requested in a supplemental application. The projects would be continuations of present projects. One is the Effect of Light on Retinal Degeneration in Albino Rats, directed by W. G. Bush, Ph.D., Assistant Professor of Biology. This research will study the effects of light on the retinas of rats and will attempt to elucidate mechanisms responsible for retinal damage. Retinal damage will be quantitatively assessed at the light and electron microscopic levels. Retinal damage will also be determined by measuring the uptake of labeled amino acids. The second project, Blood Vessels and Sweating, directed by W.T.M. Johnson, Ph.D., Professor of Chemistry, and Program Director, is two projects. The Blood Vessel study is an attempt to determine the chemical changes that occur in human arterial intima with aging and disease - using the venous intima for comparison. Amino acid composition of total intima as a function of age will be redetermined; the amino acid composition of intimal collagen and elastin will be determined; and finally the type collagen present at various ages and with disease. We will also attempt to use a parameter we have found, the Thermal Absorptivity, in an effort to assess collagen denaturation or structural changes (cross-linking, etc.) in intimal collagen and elastin. Our sweating studies are aimed at developing a simple, harmless test for breast cancer. We are looking for elevated lactate levels in breast sweat that may be associated with glycolysis of cancerous cells. Our infrared sweat test measures lactate. We have found evidence of a protein in samples of breast sweat. The iodine-starch reaction - used by Kuno in visualizing sweating - will be tested as a way to locate hot spots (enhanced sweating) in the breast.